Q1. Which of the following is a chemical change?
Q2. In a chemical equation, the substances written on the left side of the arrow are called:
Q3. Which type of reaction is represented by A + B → AB?
Q4. Which type of reaction is represented by AB → A + B?
Q5. Burning of carbon in oxygen is an example of:
Q6. What are the conditions required for rusting of iron?
Q7. Oxidation is defined as:
Q8. Reduction is defined as:
Q9. When an iron nail is dipped in copper sulphate solution, the colour of the solution changes from:
Q10. An exothermic reaction is one in which:
Q11. An endothermic reaction is one in which:
Q12. Which of the following is a physical change?
Q13. Burning of a candle shows:
Q14. Galvanisation is the process of coating iron with:
Q15. In the reaction MgO + C → Mg + CO, carbon acts as a:
Q16. Why should pickles not be stored in iron jars?
Q17. Crystallisation is a:
Q18. Which of the following is NOT a sign of a chemical reaction?
Q19. Which gas is responsible for turning lime water milky?
Q20. Respiration is an example of:
